Long-lived planting for public spaces

Planting - 4 months

Areal underplant autumn-colour trees and shrubs such as Prunus, Gleditsia, Euonymus and Acer with evergreens such as Lonicera nitida ‘Maigrün’ as an alternative to box, kept clipped as groundcover. Photo: Marianne Majerus

Six years ago, when Friederike Huth was driving back and forth from a new project in Merl, a residential quarter of the city of Luxembourg, she would note the front gardens filled with classic flowering plants – magnolias, roses and hydrangeas as the season progressed – and wondered how that atmosphere could be scaled up to work on a huge-scale residential project. This was on her mind because the contract for designing the outside space of a new housing development had just been won by her company Areal Landscape Architects. “The name of the project translates to ‘The Gardens of Luxembourg’,” she says, “and the developer took this name seriously and decided to invest in the open spaces.”

Photo: Marianne Majerus

She co-founded her practice with partner Christian Weier - they studied landscape architecture together in Berlin and set up Areal in Luxembourg in 2006. They work mainly in the city, undertaking urban master planning, public squares, parks, schools, crèches and residential projects. In Luxembourg – a country of just 2,600 sq km – there is a lot of construction going on. “Our population of 600,000 is growing by 15,000 every year, so there are lots of opportunities for landscape design.”

Friederike Huth and Christian Weier. Photo: Marianne Majerus

Dealing with development

Areal has focused mostly on public projects, working with residential and commercial developers. “The way it works here is that we design from the architect’s drawings, long before construction has even started. It means that we have to specify the planting way in advance and that is sometimes tricky. Our role is to oversee the whole outside space from design to execution and sign off, but it is the developer who actually provides the hard landscaping and planting teams,” she explains.

In the case of the Merl project, on the site of a former dairy, the planting has proved to be a big success. “We try to blur the lines between public and private open spaces by treating them with the same level of quality – and by carrying over planting schemes from one space to another, so that the whole thing holds together. “How I work is that I make a long list of maybe 70 plants, with their characteristics, and then condense that down to perhaps 20, 15, or in some cases, just five,” she says. “The main challenge is to anticipate what kind of maintenance the plants will get after the project is finished, because we are hardly ever called in to consult after the work ends. We try not to overcomplicate things.”

Allium ‘Globemaster’ is ideal for mass plantings as the seedheads stay attractive for several months. Planted with yew, hydrangea and Hemerocallis minor, a small, reliable, and long-flowering species of daylily. Photo: Marianne Majerus

Salvia nemorosa ‘Ostfriesland’ is shorter than others, and robust with a long season. For this public area at the Merl project it is planted with Hemerocallis minor, Nepeta racemosa ‘Walker’s Low’ and Sesleria glauca, a compact silvery grass which looks good in winter. Photo: Marianne Majerus

The simplicity is not only an aim, but also a necessity. On this scale, it is essential to get good groundcover. Now that Luxembourg, like Britain, gets long periods of drought in summer, lawns are kept to a minimum. In some of her projects (at Place Thorn, a nearby public square, for example), yew (Taxus baccata) is used in blocks to create neatness and a sense of intimacy; while at Merl, low-growing Lonicera nitida ‘Maigrün’ is used as an evergreen foil to the flowering plants.

To ensure year-round interest, Huth always makes a ‘timeline’ of the planting, with trees that often have two seasons (spring and autumn) as well as an interesting shape in winter. She also specifies bulbs and perennials for spring and summer, and shrubs and grasses for winter interest. “The plants themselves are not complicated, but it is vital to make sure that the ones we specify will work. For that, we are very selective about cultivars to get the right form, colour, height and length of flowering. For autumn, we use lots of asters – such as the low-growing Aster novi-belgii ‘Lady in Blue’ and Aster novi-belgii ‘Professor Anton Kippenberg’. Aster divaricatus combines well with Rudbeckia fulgida var. deamii, which carries its yellow discs deep into autumn.”

Anemone × hybrida ‘Honorine Jobert’ and Hydrangea paniculata ‘Limelight’ – good for lighting up shady areas – help transition the planting from late summer to autumn. Photo: Marianne Majerus

In early autumn, colour is provided by Amelanchier lamarckii and Rudbeckia fulgida var. deamii planted with white Aster divaricatus, good in shade. Photo: Marianne Majerus

Photo: Marianne Majerus

High and dry

Housing schemes in Luxembourg are almost always built on top of underground parking spaces, adding the problem of irrigation and nutrition. Areal always strives to get in a minimum depth of 35cm of substrata, where necessary by remodelling the ground or by adding raised borders “as high as the structural engineers will let us,” says Huth. This gives the plants some security, even if the irrigation system fails.

Increasingly, she is designing schemes without irrigation – Areal recently did a scheme for a school using simple, drought-resistant plants such as Aster divaricatus and Luzula for shade, with Aster pyrenaeus and Nepeta for sun, which have held up well in 40cm of soil. “The work happens very quickly so we rarely get a chance to try out our schemes before they go in.”

The soil is nearly always imported, but it can vary in quality and be light and lacking in nutrients. If possible, Huth specifies adding sterilised compost, which is clean and has little chance of weeds – the developer’s nightmare. “We have to plant on the upper limit of the recommended spacing, to create immediate impact and to make sure there are no weeds. We just can’t be sure when, or who, will be maintaining the spaces afterwards, so we do all we can to make sure there are no opportunities for weeds to develop.”

To make a scheme look as good as the Merl project, particularly in autumn, takes a great deal of experience – Huth and Weier are joined by a team of up to five experienced landscape architects. Huth was an intern at Kew Gardens and worked with Brita von Schoenaich in London, and both Huth and Weier have also worked for Martha Schwartz. “We feel lucky to get the work we get. Employing landscape architects on big building projects is not the norm in Luxembourg, and we rarely get asked to do private gardens. Garden design as a profession is not well known here.”

“Planting is only a small part of the whole project,” she says, “but it is often the planting that ‘carries’ the whole scheme.” She advises those embarking on their first planting designs for public spaces to limit the plant palette but repeat in quantities throughout the scheme. “You also have to know when to stop fighting – on these kind of projects, the client often doesn’t care whether the wrong cultivar has been supplied as long as it is doing the job. Sometimes we have to accept the replacements if the overall effect is still good,” Huth continues. “Use the plants you know will work. Large-scale projects are not the place for experimentation. If I want to be more adventurous, I do that in my own garden.”